Sharpe, Shaun2023-04-202023-04-202021-03-16https://hdl.handle.net/10388/14605Herbicide resistance within annual cropping systems on the Canadian Prairies has been well documented. Wild oat (Avena fatua) is a widespread and established agricultural threat with multiple resistant biotypes identified. Kochia (Kochia scoparia) is exhibiting an aggressive herbicide resistance survival strategy with biotypes which resist multiple post-emergence, in-crop, systemic modes of action. Competition dynamics between weeds are relatively understudied but may be important in predicting weed community composition shifts as a consequence of herbicide resistance evolution. The objective was to study interspecific and intraspecific interference for wild oat and kochia within the context of kochia tumbleweed mediated dispersal through wild oat infestations. Greenhouse trials were initiated in Saskatoon, SK in 2019. The experimental design was a two-factor factorial arranged as a randomized complete block. Treatment combinations involved either 0, 1, or 2 plants per pot for either species with a maximum of four plants per pot. After 81 days of competition with wild oat, kochia biomass was reduced by approximately 70%. Wild oat was largely impacted by intraspecific interference with approximately 50% biomass reduction. Should kochia's range expand due to escaping herbicidal control, it is not likely to displace wild oat though factors of allelopathy should be further considered. Additional study is required to understand how crop competition may impact competition between these weeds. Link to Video Presentation: https://youtu.be/HkshgOsaj2MenAttribution-NonCommercial-NoDerivs 2.5 CanadaHerbicide Resistance, Wild Oat, KochiaConference Presentation